Parsimony is just a preference. It doesn't really decide substantive arguments. The only case where it should really be the deciding point is when you have two theories that make exactly the same predictions. So I don't think it applies at all when you have "polar contradicting theories".

Does that poster say "LOL?" I also don't understand the significance of him carrying a soda bottle in each pocket, but I guess they're probably filled with gasoline because radical Muslims love explosions and detest safety.

Karl: She was a bit -- what's the word that you can use, cuz I don't wanna offend anyone?
Steve: Was she a homeless person?
Karl: Yeah but sort of mental homeless.

I don't know where you were going with the "parsimony is a just a preference" thing - it is the very foundation of Occam's razor.

Occam's razor just expresses a preference for parsimony. It's just a heuristic, a "best practice" kind of thing. People often misuse Occam's Razor as if it can settle an argument of substance, as if it tells you which explanation is more accurate. But in many cases, a simpler explanation is a less accurate one. In other words, an explanation is not better merely by virtue of being simpler. It must perform as well or better than a more complex explanation in order to actually be a better explanation.

Occam's razor just expresses a preference for parsimony. It's just a heuristic, a "best practice" kind of thing. People often misuse Occam's Razor as if it can settle an argument of substance, as if it tells you which explanation is more accurate. But in many cases, a simpler explanation is a less accurate one. In other words, an explanation is not better merely by virtue of being simpler. It must perform as well or better than a more complex explanation in order to actually be a better explanation.

Ah. I misunderstood you. I'm with you.

'"Luck" is people taking the laws of probability personally; Luck is the excitement of bad math.'